Currently, liquid crystal displays (LCDs) have become important tools in people's daily living and working, and the people tend to use liquid crystal display panels in more and more different environments. Under an environment having a normal temperature, a normal humidity and a normal pressure, a display panel usually does not suffers from any quality problem; however, in some harsh environments, a color filter layer in the display panel is prone to be stripped off, leading to abnormal gaps in a product, and generating undesirable bubbles in the product. In a severe case, a problem of fissure between a color filter substrate and an array substrate will even occur. Therefore, it is particularly important to correctly evaluate film adhesion (force).
However, no uniform standard is proposed for the methods for evaluating the film adhesion at present. A common method is a scotch tape testing method, which segments a sample by using a cross-cutter manually, and thus can neither ensure a constant force for segmenting the sample, nor ensure a uniform segmentation area of the sample and a consistent number of segmented units for different samples. After the segmenting process, the sample is adhered with an adhesive tape, and then data of the stripped film is determined. Since it is impossible to ensure the force segmenting the film constant, a change of the film adhesion cannot be evaluated by a precise value, nor can a degree of reliability of the film adhesion under the harsh environment can be effectively evaluated.
In addition, existing evaluation methods are conducted based on a finished product of a display unit, which not only cause waste of resources and materials, but also increase risk of undesirable batches of products, and thus belong to ex post evaluation, and are not conducive to improvement of product quality.